Loom for weaving



Dec. 27, 1932. COTTON 1,892,299

LOOM FOR WEAVING Filed Oct. 14, 1931 5 Sheets-Sheet 1 Fig.1.

//VV[//7'0/P "#8011011: 6 a) Dec. 27, 1932. R. COTTON LOOM FOR WEAVING Filed Oct. 14, 1951 3 Sheets-Sheet R. COTTON LOOM FOR WEAVING Filed 001,. 14, 1931 Fig.3.

Dec. 27, 1932.

3 Sheets-Sheet 3 Fig. 4.

//V V5 N TOR Patented Dec. 27, 1932 PAET ROBERT COTTON, 0F HASLINGDEN, ENG-LAND LOOM FOR WEAVING Application filed October 14-, 1931, Serial No 568,794, and in Great Britain Gctober 29, 1930.

The invention relates to apparatus for controlling the tension of the warp yarn in looms for weaving and is desi ned to provide mechanism to apply additional tension to the warp yarns after the shuttle has passed through the shed and during the beat-up of the weft, to relieve the tension on the warp yarns during the shedding and to gradually and automatically reduce the friction or weight on the warp beam to maintain the tension of the warp yarns practically constant as the beam diameter decreases.

The invention comprises a pivoted swinging back rest, a rod connected thereto extending to the front of the loom, a dagger mounted on the stop rod of the slay adapted to engage the connecting rod when the shuttle has passed through the shed and raise the back rest as the beat-up of the weft takes place, and a tension screw ratchet nut and pawl carried by one of the beam friction or weightinglevers connected with and operated by the back rest, whereby the tension of the spring on the weighting levers is gradually reduced as the diameter of the warps on the beam decreases.

Also in conjunction therewith a toggle lever attachment to give a quick release and quick application of the tension spring.

The invention is applicable to either fastreed or loose-reed looms and may be fitted to existing looms or incorporated in the construction of new looms, and is shown as applied to a loose-reed loom.

The invention will be fully described with reference to the accompanying drawings Fig. l a back elevation of loom showing the invention applied thereto.

Fig. 2 is an end elevation of loose reed loom.

Fig, 3 is a sectional detail of the screw and ratchet adjustment.

Figs. st, 5 and 6 are details of the toggle attachment.

Fig. 7 is a diagram showing variation of back rest deflection.

The loom for the most part (either fastreed or loose-reed) is of known construction with slay A, shuttle box, stop rod (1 on the slay and pivoted swinging back rest E controlled by a light spring 6 and the warp boa a l: and brake or friction chains Z are also of known constructionto which tension is applied by the cranked levers L. L the chains being attached at one end to the loom frame and at the other end to the horizontal arms of the cranked levers L, L A spring M dis posed between the two levers is attached to both and exerts the tension required to weight the warp beam K.

A connecting rod F is adjust-ably attached to the swinging back rest E and extends to the front of the loom with a hook or catch 7 at its forward or free end. An auxiliary or additional dagger G is attached to the stop rod (iin position to engage the hook or catch 7" on the end of the connecting rod F when the shuttle has entered a shuttle box and the slay is about to beat up.

When the shuttle enters the shuttle box the auxiliary dagge G is raised and engages the hook or catch f and carries the rod F along with the slay swinging the back rest E and raising the rail 6 putting the desired tension on the warp yarns.

A. light tension of the spring 6 only is applied to the warp yarn during the operation of shedding, the spring-controlled back rest being free to deflect forward as the sheds are opened, thus uniformly maintaining the desired light tension on the yarn. Thus the warp beam is properly tensioned precisely as the beat-up takes place, and the weft is inserted in the cloth in a suitable and u iform manner.

To effect the gradual and automatic reduc tion of the friction on the warp beam a tension screw a to which the tension screw M is attached, is fitted in the cranked lever L with a ratchet nut 12 operated by each swing- L ing movement of the back rest E.

The sprlng attachment to the lever L comprises an eyebolt N with screwed shank n and nut in the form of a ratchet wheel a O by which the screw is moved longitudlnally L of which through an angle of approximately 180 degrees, releases the spring tension completely, when the beam may be turned back by hand, or adjusted as desired. The spring tension may be replaced by hand operation of the supplementary lever in the reverse direction.

The ratchet nut n is rotated in a direction to screw it on the eyebolt shank n and reduce the tension on the spring M by a pawl R carried on an oscillating lever 1. The oscillating lever 1" is connected to the swinging back rest E b y a connecting rod R and oscillated by it whereby the forward movement of the back rest E (due to the tension of the warp yarn stretching the back rest spring 0 causes the pawl to drag back over the ratchet teeth, and the backward movement of the back rest) due to the positive action of the dagger G on the hooked connecting rod F causes the pawl to engage a tooth of the ratchet wheel and to revolve it, thereby reducing the spring tension and therefore the friction or weight on the chains encircling the beam ruffles.

The rocking pawl lever 1" is thus oscillated during every pick in synchronism with the swinging back rest E. The pawl R is moved to a definite and fixed position by each posi tive movement derived from the dagger G and hooked connecting rod F. The extent of the pawl movement, however, depends upon the tension of the warp yarn at any particular time. 7

If the warp yarn is relatively slack, the extent of the back rest movement is very small, and consequently the pawl B does not drag back far enough to engage the next tooth on the ratchet Wheel a As weaving proceeds and the warp becomes tighter, the eX- tent of the back rest movement increases, and the pawl R drags back far enough to engage the next tooth on the ratchet wheel N which is revolved during the positive movement.

Referring to diagram Fig. 7 which shows the relative positions of the rail e of the back rest E. The back rest E is positively moved to A at each beat-up. During shedding the yarn deflects the back rest to B. This movement from A to B is not suflicient to enable the pawl R to engage a new tooth on ratchet nut n As the warp becomes tighter, the back rest is deflected further to C during shedding and this is eventually sufiicient to allow the pawl R- to engage a new tooth, and rotate the ratchet nut n one tooth, to reduce very minutely the warp brake spring tension.

The spring tension and therefore the braking effect of the chains encircling the beam ruffles are thereby reduced by very small decrements as the beam diameter decreases, the frequency of these decrements being governed by the tension of the warp yarn itself, as measured by the deflection of the back rest during the period this is spring-controlled, and particularly at the time the shed is fully o ened. e

What claim as my invention and desire to protect by Letters Patent is 1. In a loom for weaving, apparatus for controlling the tension of the warp yarns comprising in combination a swinging back rest over which the warp yarns pass, a connecting rod connected thereto extending to the front of the loom, a catch at the free end of said connecting rod, a dagger affixed on the stop rod of the slay adapted to engage the connecting rod as the slay beats-up and rock the back rest, two cranked beam weighting levers pivoted to the loom frame to the horizontal arms of which the chains or ropes from the warp beam rufiles are attached, an adjust-able spring disposed between and connecting the two vertical arms, a tension screw and ratchet nut and pawl adjustment for the spring and means to connect the screw and ratchet nut with the swinging back rest to gradually reduce the tension of the spring and the weight upon the warp beam as the diameter of the warps on the beam decreases.

2. In a loom for weaving constructed with a swinging back rest connected to and positively operated by the slay at each beat up and two cranked levers having an adjustable spring disposed between them to which weighting chains are attached to apply friction to the warp beam, the combination therewith of a tension. screw carried by one of the levers to which the spring attached, a ratchet nut on the screw, a pawl to rotate the nut and means to connect the pawl with the swinging back rest and to rock it whereby the tension of the spring on the levers is gradually reduced as the diameter of the warps on the beam decreases.

In testimony whereof I have hereunto set my hand.

ROBERT COTTON. 

